Hot water boiler



FIG. 1 is a perspective view of a hot water boiler according to the present invention.

FIG. 2 is a front view of the hot water boiler of FIG. 1.

FIG. 3 is a rear view of the hot water boiler of FIG. 1.

FIG. 4 is a left side view of the hot water boiler of FIG. 1.

FIG. 5 is a right side view of the hot water boiler of FIG. 1; and,

FIG. 6 is a top view of the hot water boiler of FIG. 1.

The part of the drawings shown in broken line, illustrates a portion of the hot water boiler that forms no part of the claimed design. 

CLAIM The ornamental design for a hot water boiler, as shown and described. 